Circuit breaker including ratchet and pawl spring charging means and ratchet teeth damage preventing means

ABSTRACT

A circuit breaker characterized by spring closing means for closing contacts, means for charging the spring closing means and including a crank shaft and a disk fixedly mounted on the shaft, a ratchet wheel rotatably mounted on the shaft and having an arcuate pin-receiving slot, a pin on the disk and extending into the slot, whereby upon release of the spring closing means from the charged position any charged stored energy causes oscillations in the shaft and disk which oscillations are dissipated by the pin oscillating in the ratchet slot without damage to the ratchet teeth.

United States Patent McGuffie [451 Sept. 5, 1972 [54] CIRCUIT BREAKER INCLUDING RATCHET AND PAWL SPRING CHARGING MEANS AND RATCHET TEETH DAMAGE PREVENTING MEANS [72] Inventor: Alan G. McGuffie, Pittsburgh, Pa.

[73] Assignee: Westinghouse Electric Corporation,

Pittsburgh, Pa.

[22] Filed: Sept. 16, 1971 [21] Appl. No.: 181,012

[52] US. Cl. ..200/153 SC, 185/40 R, 200/153 V,

[51] Int. Cl. ..H0lh 3/30 [58] Field of Search ..200/153 SC, 153 V; 335/76, 335/171, 140; 185/40 R; 74/575, 577 R, 149,

[56] References Cited UNITED STATES PATENTS 3,581,028 571971 Valbong ..200/153 V X 3,585,330 6/1971 Bould ..200/153 SC 3,600,538 8/1971 Puzas ..200/153 SC 3,627,937 12/1971 Swanke et a] ..200/153 V X Primary Examiner-Robert K. Schaefer Assistant Examiner-Robert A. Vanderhye Attorney-A. T. Stratton et a1.

[ ABSTRACT A circuit breaker characterized by spring closing means for closing contacts, means for charging the spring closing means and including a crank shaft and a disk fixedly mounted on the shaft, a ratchet wheel rotatably mounted on the shaft and having an arcuate pin-receiving slot, a pin on the disk and extending into the slot, whereby upon release of the spring closing means from the charged position any charged stored energy causes oscillations in the shaft and disk which oscillations are dissipated by the pin oscillating in the ratchet slot without damage to the ratchet teeth.

19 6 Drawing Figures PATENTEUSEP' 5 I972 SHEET 2 OF 6 V//HrVV/////lh II /Ill PATENTEDSEP 51972 SHEET l 0F vdE PATENTEDSEP 5 I972 SHEET 5 0F 6 PATENTEDSEP 51912 3 689721 SHEET 6 BF 6 CIRCUIT BREAKER INCLUDING RATCHET AND PAWL SPRING CHARGING MEANS AND RATCHET TEETH DAMAGE PREVENTING MEANS CROSS REFERENCES TO RELATED APPLICATIONS This invention is an improvement over the inventions disclosed in the application of N. J. Patel, Ser. No.

770,236, filed Oct. 24, 1968 (now US. Pat. No. 3,544,931), of Fred Bould et a1, Ser. No. 770,296, filed Oct. 24, 1968, (now US. Pat. No. 3,590,192), and of Fred Bould, Ser. No. 874,648, filed Nov. 6, 1961 now U.S. Pat. No. 3,600,540. The circuit breaker herein disclosed is generally described in the foregoing applications.

7 BACKGROUND OF THE INVENTION breakers, such as shown in us. Pat. No. 3,183,332, is-

sued May 11, 1965 to R. E. Frink et al, consist of a ratchet wheel rigidly coupled to a crank shaft and driven by a motor through a reciprocable driving pawl. A holding pawl constrains the ratchet wheel from returning to its discharged position during cycling of the driving pawl. An advantage of this type of circuit breaker is that it provides a stored-energy closing mechanism which is simple, efiicient, and economical to operate.

A disadvantage of such mechanisms is a tendency to strip teeth from the ratchet upon release of the charged closing springs. The crank shaft rotating at a high angular velocity during the closing operation can overshoot the spring discharged position by 90 or more and result in violent oscillations about that position and prevent the holding pawl from fully engaging the ratchet teeth. This has resulted in chipped or broken ratchet teeth.

Associated with the foregoing has been a problem of storing energy in a spring by electrically operated means such as a motor or by manually operated means. The problem is particularly acute where a charging motor operating at about 500 rpm to actuate a driving pawl on a ratchet wheel continues rotating under momentum after it has been deenergized by an appropriate limit switch when the closing spring reaches the fully charged position.

SUMMARY OF THE INVENTION It has been found in accordance with this invention that the foregoing problems may be overcome by providing a ratchet wheel which is rotatably mounted, rather than fixedly mounted, on the spring crank shaft. In addition the ratchet wheel is provided with a pinreceiving arcuate slot. A disk which is fixedly mounted on or integrally formed with the crank shaft in a position adjacent to the ratchet wheel is provided with a pin which extends into the arcuate slot, whereby upon release of spring from the charged position the disk oscillates with the crank shaft and the pin on the disk oscillates within the arcuate slot in the ratchet wheel to prevent damage to the ratchet wheel teeth in the manner described above with respect to the prior art constructions.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an end view, with parts broken away and with some parts omitted for the purpose of clarity, of a circuit breaker constructed in accordance with the principles of this invention;

FIG. 2 is a sectional view taken generally along the line Il-II of FIG. 1;

FIG. 3 is an enlarged, fragmentary end view of the ratchet wheel mechanism;

FIG. 4 is a sectional view with parts broken away and certain parts omitted for the purpose of clarity, of the spring and sprocket wheel mechanism in the discharged position, and taken generally the line lV IV of FIG. 3;

FIG. 5 is a sectional view of the device shown in FIG. 4 in the charged position; and

FIG. 6 is an exploded view of the sprocket wheel mechanism in the discharged condition taken generally in the direction of the line VIVI of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, there is shown in FIG. 1 and 2 a three-pole circuit breaker 5 comprising a support structure or housing structure 7 and a circuit breaker structure 9 supported on the housing structure. The housing structure 7 comprises a metallic base plate 11, a pair of spaced metallic side plates 13 fixedly secured to flanges of the base plate, a pair of metallic center plates 17 fixedly mounted on the base plate, and a back wall structure indicated generally at 19.

The circuit breaker structure 9 is a three-pole structure comprising a stationary contact 21 (FIG. 2) and a movable contact 23 for each pole unit. Each of the movable contacts 23 is supported on a conducting contact arm 25 that is pivotally supported on a terminal conductor 27 by means of a pivotal support means 29. In each pole unit, a separate insulating connecting member 31 is pivotally connected at one end thereof to the contact arm 25 and at the other end thereof to a lever 33 that is welded to a common jack shaft 35 that extends across all of the poles of the circuit breaker. There is a separate lever 33 for each pole unit welded to the common jack shaft 35. Only one of the contact structures is shown in FIG. 1. The contact structures for the center pole and for the lefthand FIG. 1) pole are omitted from the drawing in FIG. 1 merely for clarity. It can be understood that the contact structures for all three pole units are the same as the one contact structure shown in FIGS. 1 and 2.

The jack shaft 35 is supported for pivotal movement, about the elongated axis thereof, on the side plates 13 and center plates 17. The connecting member 31, levers 33, and jack shaft 35 are part of a stored-energy spring-closing mechanism 39 (FIG. 2) that is operable to close the contacts 23, 21. The mechanism 39 comprises a link 41 that is pivotally connected, at one end thereof, to the lever 33 of the center pole by means of a pin 43. The link 41 is pivotally connected at the other end thereof, to a link 45 by means of a knee pivot pin 47. A roller member 49, that serves as a cam follower, is mounted on the pin 47 to cooperate with a closing cam 51. The link 45 is pivotally connected at the other end thereof to a latch member 53 by means of a pin 55. The latch member 53 is mounted for pivotal movement about a fixed pivot pin 57 that is supported on the lefthand (FIG. 1) center plate 17.

A tension spring 59 is connected to the pin 55 to reset the linkage following a tripping operation of the circuit breaker. The latch member 53 engages the periphery of a trip shaft 63 in proximity to a cutout portion of the shaft, which cut-out portion is provided so that when the trip shaft 63 is rotated in a counterclockwise direction, the latch member 53 will be free to move into the cut-out portion to the tripped position. The trip shaft 63 is supported for pivotal movement about the elongated axis thereof between one of the center plates 17 and one of the side plates 13.

A roller latch 67 (FIG. 2) is rotatably supported on and between the twin plates of the closing cam 51. The closing cam 51 is fixedly secured to a crankshaft 71 that is rotatably supported on suitable bearings that are secured to the center plates 17. A pair of crank arms 73 are fixedly mounted on the crank shaft 71 at the opposite ends of the crank shaft 71. As shown in FIGS. 4, 5, and 6 driving connection means generally indicated at 72 are provided for charging the closing spring means and include a projection and projection-receiving slot which are described more particularly below. A ratchet member of wheel 74 is rotatably mounted on the crank shaft 71 and a rotatable member or disk 75 is fixedly mounted on the crank shaft. The wheel 74 and disk 75 are preferably adjacent to each other. The disk 75 has a projection or pin 76 extending from one side and parallel to the axis of the shaft 71. The crank shaft 71, crank arms 73, disk 75, and projection 76 move in unison as a crank-shaft structure 76a. The wheel 74 includes an arcuate slot 77 into which the pin 76 extends. The slot 77 extends through an arc of at least 90 and preferably about 180. Though the pin 76 and the slot 77 are preferably disposed in the disk 75 and wheel 74, respectively, their positions may be reversely disposed without affecting their operative relationship; that is, the pin and slot may be in the wheel and disk, respectively. A reciprocating member 78 (which is described more particularly hereinbelow), is rotatably mounted on the peripheral surface of the disk 75 where it is supported for pivotal reciprocating movement relative to the crank shaft 71 to cooperate with the ratchet 74.

A separate tension spring 79 is operatively connected at the end of each of the crank arms 73 by means of a pivot pin 80. Each of the springs 79 is connected to a spring support 81 that is pivotally connected to the associated arm 73 by means of the associated pivot pin 80. Each of the tension springs 79 is connected, at the other end thereof, to a rod 82 that is secured to the center plate 17. A manual operating mechanism, indicated generally at 83 (FIG. 1), is provided for manually charging the closing springs 79. A latch member 85 (FIG. 2) is pivotally mounted on a pin 87 and biased in a clockwise (FIG. 2) direction to the latching position wherein the latch 85 engages the roller 67 to latch the closing cam 51 and crank shaft 71 to prevent counterclockwise movement of the closing cam 51 and crank shaft 71.

The circuit breaker is shown in FIG. 2 in the contact open position with the stored energy closing springs 79 in the charged condition. The spring support pins of the tension springs 79 are below a line between the center of the spring support rod 82 and the axis of the crank shaft 71 so that the charged tension springs 79 are operating to bias the crank shaft 71 in a counterclockwise direction. Counterclockwise movement of the crank shaft 71 is prevented by the engagement of the latch member with the latch roller 67 that is mounted on the closing cam 51. The latch member 85 is operated to the unlatching position to close the circuit breaker in a manner described in the above-mentioned US. Pat. No. 3,590,192. When it is desired to close the breaker, the latch 85 is pivoted in a counterclockwise (FIG. 2) direction to thereby release the roller 67. When the roller 67 is released, the closing cam 51 and the crank shaft 71 are free to rotate in a counterclockwise direction, and the closing springs 79, operating on the crank arms 73, operate to rotate the crank shaft 71 in a counterclockwise direction as the springs 79 discharge. During this movement, the closing cam 51 will force the roller 49 and the link 41 upwardly to the closed position. During this closing movement of the link 41 of the lever 33 (FIG. 2) of the center pole unit is forced in a counterclockwise direction to rotate the jack shaft 35 counterclockwise to simultaneously move the three contact arms 25 in a clockwise direction about the pivots 29 to the closed position. In the closed position, the engagement of the closing cam 51 with the roller 49 serves to prop the link member 41 in the closed position to thereby maintain the jack shaft 35 and contacts 23 in the closed position.

With the contacts in the closed position and the closing spring 79 discharged, the circuit breaker may be automatically tripped open, in response to an overload above a predetermined value in any of the pole units, by operation of the trip shaft 63 in a manner described in the US. Pat. No. 3,544,931. During the tripping operation, the trip shaft 63 is rotated in a counterclockwise (FIG. 2) direction. When the trip shaft 63 is rotated counterclockwise, the trip shaft moves to permit the latch member 53 to move into the cut-out portion of the trip shaft 63, thereby permitting the latch member 53 to move in a counterclockwise direction about the pivot 37 to the tripped position. The compressed contact spring 93 (FIG. 2) and an opening spring 99 (FIG. 1) then operate to move the contact arms 25 toward the open position which movement occur because the pivot 55 is free to move so that the link 45 can move to the tripped position with the toggle 45,41 collapsing to permit the lever 33 and jack shaft 35 to move in a clockwise direction to the tripped open position. Thus, movement of the trip shaft 63 to the tripped position permits the members 41, 45, 53 to move to the tripped position, wherein the roller 49 and link 41 no longer restrain the lever 33 in the closed position, and the springs 93, 99 operate to move the jack shaft 35 and the three contact arms 25 to the tripped open position.

With the circuit breaker in the tripped open position, the breaker is reset and the closing springs 79 are charged by operation of a drive motor 101 (P16. 3) in a manner to be hereinafter more specifically described. In order to reset the circuit breaker and charge the closing springs 79, the crank arm 73 is rotated from the spring discharged position of FIG. 4 through an angle of more than 180 to the spring charged position of FIGS. 2 and 5. As the crank shaft 71 moves to the position seen in FIG. 2, the roller 49 rides off of the peak of the cam 51 into the depression seen in FIG. 2. When the roller 49 is free to move into the depression of the cam 51, the spring 59 (FIG. 1) biases the latch 53 clockwise (FIG. 2) to move the latch 53 to the reset position pulling links 45, 41 and the roller 49 to the reset position wherein the roller 49 is positioned in the depression of the cam 51 (FIG. 2). When the latch 53 moves out of the notch of the trip shaft 63, suitable spring means operates to rotate the trip shaft 63 clockwise to the latching position wherein the periphery of the trip shaft 63 again latches the latch member 53 to latch the parts in the reset position seen in FIG. 2. As the crank shaft 71 moves more than 180 to the position seen in FIGS. 2 and 5, the springs 79, which are moved over center, take over to bias the crank shaft 71 in a counterclockwise (FIG. 2) direction, and the roller 67 engages the latch 85 to latch the crank shaft 71 in the charged position seen in FIG. 2, and the circuit breaker is prepared for another closing operation.

When the circuit breaker is in the contact-closed position with the stored energy closing springs 97 discharged the spring closed means is operated to the charged position by operation of the motor drive structure 101 (FIG. 1) rotate the crank shaft 71 through an angle of slightly more than 180 (approximately 184) to charge the springs 79 during which movement the roller 49 rides on a fixed radius of the cam 51 to a position just short of the peak of the cam surface of the cam member 51. This charging movement of the cam 51 is more specifically described in the above-mentioned US. Pat. No. 3,590,192.

With the parts in the contact closed spring charged position, the following sequence of operations can occur.

Upon the occurrence of an overload above a predetermined value, the trip means indicated generally at 95 (FIG. 1) is automatically operated to rotate the trip shaft 63 to release the latch member 53 and permit the toggle 41, 45 to effect an opening operation in the same manner as was hereinbefore described. With the toggle 41, 45 collapsed, the spring '59 operates to draw the roller 49 into the depression of the cam 51 resetting the linkages 53,41, 45 and the trip shaft 63 is moved by spring means into the latching reset position seen in FIG. 2. The parts at the end of this tripping operation are in the position seen in FIG. 2, wherein the mechanism is reset and relatched, and wherein the roller member 49 is in the depression of the cam 51 so that the parts are prepared for a closing operation. When the closing springs 79 are charged, an operator can immediately operate the closing latch (FIG. 2) to release the roller 67, whereupon the circuit breaker is operated to the closed position. With the parts in the closed position, if an overload above the predetermined value occurs the trip means will be automatically operated to rotate the trip shaft 63 to the tripped position to effect a tripping operation in the same manner described above. With the parts in the tripped position and the closing springs 79 discharged, another charging operation of the closing springs 79 will be required in order to provide another closing operation. Thus, when the circuit breaker is in the contact closed spring charged position, the circuit breaker can be tripped and then closed and then tripped again in rapid sequence.

The reciprocating member 78 (FIGS. 4, 5, and 6) comprises a frame forming a circular opening 106, and a flange or bight portion 107. The reciprocating member 78 is rotatably mounted on the peripheral surface of the disk 75 for movement relative to the crank shaft 71 about the axis of the crank shaft 71. A charge pawl 109 is pivotally mounted on the reciprocating member 78 by means of a pin 113, and a torsion spring biases the pawl 109 in a counterclockwise direction about the pin 113 into engagement with the ratchet wheel 75. A tension spring 117 biases the reciprocating member 78 in a clockwise direction about the crank shaft 71. Two holding pawls 121 and 122 are pivotally mounted on one of the center plates 17 by means of pins 123 and biased in a counterclockwise direction, by means of torsion springs 125, into engagement with the ratchet wheel 75. The pawls 121 and 123 are spaced from each other by a distance greater than the length of the toothless portion 154 in order to assure engagement of at least one holding pawl on the ratchet at all times.

The drive motor 101 comprises an output shaft 133 (FIGS. 3, 4 and 5). An arm 137 is mounted on the end of the shaft 133 and a roller member 139 is rotatably mounted on a pin 141 that is supported on the arm 137.

As can be seen in FIG. 5, the closing springs 79 are in the charged position with the closing latch 85 (FIG. 2) engaging the roller 67 of the cam 51 to latch the crank shaft 71 in the spring charged position shown in FIG. 2. Upon the release of the latch 85, the springs 79 discharge rotating the crank shaft 71 approximately to close the circuit breaker. Upon discharge of the closing springs 79 suitable limit switch means is actuated in a well known manner by the breaker mechanism to energize the drive motor 101. Upon energization of the drive motor 101, the arm 137 is rotated in a clockwise (FIG. 4) direction about the axis thereof at a suitable rate such as 500 rpm.

During each revolution of the output shaft 133, the roller 139, operating against the bight portion 107 of the reciprocating member 78 moves the reciprocating member in a counterclockwise direction during which movement the charge pawl 109 operates against one of the teeth of the ratchet 74 to advance the ratchet and crank shaft 71. As the roller am 137 moves 180 from the position seen in FIG. 4, the reciprocating member 78 will advance the ratchet 74 and crank shaft 71 in a counterclockwise direction, and as the roller arm 137 moves the remaining 180 of a 360 revolution, the spring 117 will return the reciprocating member 78 to the position seen in FIG. 4. with the holding pawls 121 and 122 holding the ratchet 75 and crank shaft 71 in the advanced position.

As the ratchet wheel 74 rotates counterclockwise, the forward end or projection-engaging surface 77a of the slot 77 contacts the pin 76 (FIGS. 4 and S) and drives the disk 75. As the output shaft structure 133 rotates, the ratchet 75 is advanced by the charge pawl 109 and alternately held by the holding pawls 121 and 122 until the crank shaft 71 moves more than 180 to an over-center position wherein the charged closing springs 79 again bias the crank shaft 71 in a counterclockwise direction with the ratchet 75 and crank shaft 71 becoming latched from closing movement by the latch member 85 (FIG. 2) which engages the roller 67 on the cam 51 that is fixed to the crank shaft 71. When the closing springs 79 reach the fully charged position, the charge pawl 109 is adjacent a missing tooth portion 154 (FIG. 5) of the ratchet 75 so that continued rotation of the motor will not operate against the teeth of the ratchet 75, and the motor can be brought to a stopped condition without damaging the parts and without putting undue forces on the parts. The motor 101 is automatically deenergized by suitable limit switch means in a manner well known in the art.

Upon the release of the springs 79, the pin 76 rotates to a reverse end 77b of the slot 77 an drives the ratchet wheel 75 to a reset position (FIG. 4) preparatory to recharging of the springs 79. In that position the missing tooth portion 154 is located counterclockwise beyond the position of the holding pawl 121 or 122. When the springs 79 reach the discharged position (FIG. 4), the pivot pin 80 can overshoot the dead center position due to the high velocity developed and the oscillate clockwise and counterclockwise with reducing amplitude until the energy is completely dissipated. During this dissipation period the pin 76 oscillates freely in the slot 77 until stopping in the position shown in FIG. 4.

What is claimed is:

l. A circuit breaker comprising a pair of contacts operable between open and closed positions, a crank shaft structure supported for rotational movement, closing spring means connected to said crank shaft structure, a ratchet wheel supported for movement relative to said crank shaft structure, operating means comprising pawl means operable to advance said ratchet wheel, driving connection means between said ratchet wheel and said crank shaft structure, said operating means being operable to operate said pawl means to advance said ratchet wheel during which movement said ratchet wheel operates through said driving connection means to rotate said crank shaft structure from a spring discharged position to a spring charged position to charge said closing spring means said closing spring means being dischargeable and upon discharge thereof moving said crank shaft structure to said spring discharged position to thereby operate said contacts to the closed position, and said driving connection means permitting movement of said crank shaft structure relative to said ratchet wheel upon movement of said crank shaft structure to said spring discharged position.

2. A circuit breaker according to claim 1, said circuit breaker comprising releasable latch mean latching said crank shaft structure in said spring charged position,

and upon release of said latch means said closing spring means discharging to move said crank shaft structure to said spring discharged position.

3. A circuit breaker according to claim 1, wherein said driving connection means comprises a projection on one of said ratchet wheel and crank shaft structure and a projection-engaging surface on the other of said ratchet wheel and crank shaft structure.

4. A circuit breaker according to claim 3, wherein said projection is on the crank shaft structure and said projection-engaging surface is on the ratchet wheel.

5. A circuit breaker comprising a pair of contacts movable relative to each other between open and closed positions, closing spring means operable to a charged condition for moving the contacts to the closed position, means for charging the spring means and including a crank shaft and a ratchet rotatable with respect to the crank shaft, driving connection means on said ratchet and rotatable member providing a driving connection between the ratchet and the rotatable member during charging of the closing spring means, the driving connection means permitting the rotatable member to move relative to the ratchet upon discharge of the charging spring means, the charging means also including a reciprocating charge pawl operable to advance the ratchet, for charging the closing spring means, holding pawl means for constraining the ratchet, and means for releasing the closing spring means from the charged condition and operatively connecting the spring means with at least one of the contacts for moving the contacts to the closed condition.

6. The circuit breaker of claim 5, wherein the driving connection means includes a pin extending from one of the ratchet and rotatable means and a pin-engaging surface on the other of the ratchet and rotatable means.

7. A circuit breaker comprising a pair of contacts movable relative to each other between opened and closed positions, closing spring means operable to a charged condition for moving the contacts to the closed position, means for charging the spring means and including a crank shaft and a ratchet wheel rotatable on the axis of the crank shaft, rotatable means fixedly mounted on the crank shaft, one of the ratchet wheel and rotatable means having an arcuate pinreceiving slot therein and the other of the ratchet wheel and rotatable means having a pin extending into the arcuate slot, the charging means also including a reciprocating charge pawl operable to advance the ratchet wheel charging the closing spring means, holding pawl means for constraining the ratchet wheel, means for releasing the closing spring means from the charged condition and including link means operatively connecting the spring means with at least one of the contacts for moving the contacts to the closed position, whereby charged stored energy in the discharged spring means causes any oscillations in the crank shaft and rotatable means to be dissipated by the pin oscillating in the arcuate slot without damage to the ratchet wheel teeth by the drive and holding pawls.

8. The circuit breaker of claim 7 in which the ratchet wheel includes the arcuate pin-receiving slot and the rotatable means includes the pin extending into the slot.

9. The circuit breaker of claim 7 in which the arcuate slot extends through an arc of from about to about of the ratchet wheel.

10. The circuit breaker of claim 7 in which the arcuate slot includes pin-engaging end walls.

11. The circuit breaker of claim 7 in which the rotatable means is a disk. N

12. The circuit breaker of claim 7 in which a charge pawl is reciprocable on the axis of the crank shaft.

13. The circuit breaker of claim 1 1 in which an annular member is rotatably mounted on the disk, the charge pawl is mounted on the annular member, the annular member being spring biased in a direction opposite that of charge pawl engagement with the ratchet wheel, and the annular member having a bight portion operative by the charging means in the direction opposite that of the spring bias.

14. The circuit breaker of claim 13 in which the means for charging the spring means also includes a reciprocating member and movable to advance and retract the charge pawl.

15. The circuit breaker of claim 14 in which the reciprocating member is rotatably mounted with respect to the crank shaft.

16. The circuit breaker of claim 14 in which the reciprocating member is rotatably mounted on the crank shaft.

17. The circuit breaker of claim 14 in which the charge pawl is mounted on the reciprocating member.

18. The circuit breaker of claim 14 in which means for disengaging the charge pawl are provided on one of the ratchet and the rotatable means.

19. The circuit breaker of claim 7 in which the charging means includes a drive motor operable to charge the closing spring means. 

1. A circuit breaker comprising a pair of contacts operable between open and closed positions, a crank shaft structure supported for rotational movement, closing spring means connected to said crank shaft structure, a ratchet wheel supported for movement relative to said crank shaft structure, operating means comprising pawl means operable to advance said ratchet wheel, driving connection means between said ratchet wheel and said crank shaft structure, said operating means being operable to operate said pawl means to advance said ratchet wheel during which movement said ratchet wheel operates through said driving connection means to rotate said crank shaft structure from a spring discharged position to a spring charged positIon to charge said closing spring means said closing spring means being dischargeable and upon discharge thereof moving said crank shaft structure to said spring discharged position to thereby operate said contacts to the closed position, and said driving connection means permitting movement of said crank shaft structure relative to said ratchet wheel upon movement of said crank shaft structure to said spring discharged position.
 2. A circuit breaker according to claim 1, said circuit breaker comprising releasable latch mean latching said crank shaft structure in said spring charged position, and upon release of said latch means said closing spring means discharging to move said crank shaft structure to said spring discharged position.
 3. A circuit breaker according to claim 1, wherein said driving connection means comprises a projection on one of said ratchet wheel and crank shaft structure and a projection-engaging surface on the other of said ratchet wheel and crank shaft structure.
 4. A circuit breaker according to claim 3, wherein said projection is on the crank shaft structure and said projection-engaging surface is on the ratchet wheel.
 5. A circuit breaker comprising a pair of contacts movable relative to each other between open and closed positions, closing spring means operable to a charged condition for moving the contacts to the closed position, means for charging the spring means and including a crank shaft and a ratchet rotatable with respect to the crank shaft, driving connection means on said ratchet and rotatable member providing a driving connection between the ratchet and the rotatable member during charging of the closing spring means, the driving connection means permitting the rotatable member to move relative to the ratchet upon discharge of the charging spring means, the charging means also including a reciprocating charge pawl operable to advance the ratchet, for charging the closing spring means, holding pawl means for constraining the ratchet, and means for releasing the closing spring means from the charged condition and operatively connecting the spring means with at least one of the contacts for moving the contacts to the closed condition.
 6. The circuit breaker of claim 5, wherein the driving connection means includes a pin extending from one of the ratchet and rotatable means and a pin-engaging surface on the other of the ratchet and rotatable means.
 7. A circuit breaker comprising a pair of contacts movable relative to each other between opened and closed positions, closing spring means operable to a charged condition for moving the contacts to the closed position, means for charging the spring means and including a crank shaft and a ratchet wheel rotatable on the axis of the crank shaft, rotatable means fixedly mounted on the crank shaft, one of the ratchet wheel and rotatable means having an arcuate pin-receiving slot therein and the other of the ratchet wheel and rotatable means having a pin extending into the arcuate slot, the charging means also including a reciprocating charge pawl operable to advance the ratchet wheel charging the closing spring means, holding pawl means for constraining the ratchet wheel, means for releasing the closing spring means from the charged condition and including link means operatively connecting the spring means with at least one of the contacts for moving the contacts to the closed position, whereby charged stored energy in the discharged spring means causes any oscillations in the crank shaft and rotatable means to be dissipated by the pin oscillating in the arcuate slot without damage to the ratchet wheel teeth by the drive and holding pawls.
 8. The circuit breaker of claim 7 in which the ratchet wheel includes the arcuate pin-receiving slot and the rotatable means includes the pin extending into the slot.
 9. The circuit breaker of claim 7 in which the arcuate slot extends through an arc of from about 90* to about 130* of the ratchet wheel.
 10. The circuit breaker of claim 7 in which the arcuate slot includes pin-engaging end walls.
 11. The circuit breaker of claim 7 in which the rotatable means is a disk. N
 12. The circuit breaker of claim 7 in which a charge pawl is reciprocable on the axis of the crank shaft.
 13. The circuit breaker of claim 11 in which an annular member is rotatably mounted on the disk, the charge pawl is mounted on the annular member, the annular member being spring biased in a direction opposite that of charge pawl engagement with the ratchet wheel, and the annular member having a bight portion operative by the charging means in the direction opposite that of the spring bias.
 14. The circuit breaker of claim 13 in which the means for charging the spring means also includes a reciprocating member and movable to advance and retract the charge pawl.
 15. The circuit breaker of claim 14 in which the reciprocating member is rotatably mounted with respect to the crank shaft.
 16. The circuit breaker of claim 14 in which the reciprocating member is rotatably mounted on the crank shaft.
 17. The circuit breaker of claim 14 in which the charge pawl is mounted on the reciprocating member.
 18. The circuit breaker of claim 14 in which means for disengaging the charge pawl are provided on one of the ratchet and the rotatable means.
 19. The circuit breaker of claim 7 in which the charging means includes a drive motor operable to charge the closing spring means. 